Elon Musk has a history of wild ideas — some of them have worked out

The appointment of Robyn Denholm to chairwoman briefly boosted Tesla share prices to levels seen before Musk's infamous tweet that he had "funding secured" to take the company private at $420 a share.

Elon Musk may or may not be launching a "Yelp (YELP) for Journalists" — according to a Wednesday Twitter tirade from the serial tech entrepreneur.

The journalism review site, potentially named Pravda after the former Soviet Union propaganda newspaper, is the latest in Musk's long history of wild ideas.

He's teased a food and beverage venture, sold out branded flamethrowers and he challenged himself to build a battery of record size in under 100 days.

There's something to be said for the constant hype and media distraction of it all, particularly while one of Musk's main ventures continues to struggle. Tesla (TSLA) has suffered from ongoing Model 3 delays, painful stock dips and reports of inadequate working conditions in its factories.

But Musk — who has already made his name with PayPal, SpaceX, SolarCity and newspaper publishing software Zip2 — continues to propose new projects. Here are some of the strangest ideas, and some of the most successful:

Boring Candy

Just this month Musk said he would be starting a candy company. The announcement was inspired by a spar with legendary investor Warren Buffett .

The CEO of Berkshire Hathaway, which owns See's Candies, noted Musk's history of disrupting industries and said: "Elon may turn things upside down in some areas. I don't think he'd want to take us on in candy."

Musk posted a picture of Boring Candy to his Instagram account just weeks later. He's since deleted the post.

Flamethrowers

Musk announced in December that his Boring transportation company would start selling flamethrowers.

The Boring-branded gadgets were an encore to the company's signature hats — and a little closer to blow torches.

The company sold 20,000 units — or $10 million worth — in just five days .

100 days to build the world's biggest battery

Last year Musk's electric car company Tesla won a bid to build the world's biggest battery system in Southern Australia . Musk had already committed to the endeavor on Twitter when he gave himself an high-stakes deadline.

The battery system can power 30,000 homes and draws energy from a nearby wind farm. It was completed, as promised, in under 100 days .

Underground Hyperloop

Nearly five years ago, Musk released a white paper on the idea of high-speed underground transportation tubes. The idea was Hyperloop —"some enlarged version of the old pneumatic tubes used to send mail and packages within and between buildings"— could ease urban congestion and reduce travel times.

The project has evolved in the years since, adopted by outside start-ups and tying in insights and technology from Tesla's other futuristic start-up SpaceX. Musk tweeted earlier this month that he hopes the pods reach "half speed of sound."

Musk has also shepherded the adoption of the Hyperloop pods with The Boring Company, which theorizes that "fast to dig, low cost tunnels would also make Hyperloop adoption viable and enable rapid transit across densely populated regions, enabling travel from New York to Washington DC in less than 30 minutes."

Musk last week teased the public opening of the first tunnel under Los Angeles , including free rides starting "in a few months."

Reusable rockets

Musk founded SpaceX to establish a human colony on Mars but along the way he set a company goal to reduce the cost and time it takes to reach space. The company has achieved a myriad of milestones since its founding but reuse was only realized in the last few years.

In December 2015, SpaceX took a first massive step towards reusability when it became the first company to land part of an orbital rocket. Just over a year later, SpaceX took another giant step, by launching and landing a Falcon 9 rocket it launched and landed once before.

Next up? Musk wants SpaceX to launch and land a rocket twice in 24 hours – as early as next year. It's all a part of his plan to make his rockets "like a commercial airliner," Musk said.

—CNBC's Michael Sheetz contributed to this report.